Low and slow scratch build

[Swifted]

Joined a rocket club a couple of months ago because I thought it would be fun with my 4 year old… now I’m obsessed.
I have a laser cutter and 3d printer and the mail is too slow, so I put this together out of those tubes the vinyl cutter vinyl comes on. Comes out to 32 inches with an 8 inch 3d printed nosecone, BT is about 1 5/8”. It sims to about 700’ on an E, just waiting on some bt-50 tubing to get here to do the MMT. I decided to have fun with the fins to see what I could do with the laser cutter (it’s new!) and some epoxy. Didn’t think to paint before cutting so I’ll just have to do a paint scheme that goes with plywood once the rain stops.

 

[lakeroadster]

Joined a rocket club a couple of months ago because I thought it would be fun with my 4 year old… now I’m obsessed.
I have a laser cutter and 3d printer and the mail is too slow, so I put this together out of those tubes the vinyl cutter vinyl comes on. Comes out to 32 inches with an 8 inch 3d printed nosecone, BT is about 1 5/8”. It sims to about 700’ on an E, just waiting on some bt-50 tubing to get here to do the MMT. I decided to have fun with the fins to see what I could do with the laser cutter (it’s new!) and some epoxy. Didn’t think to paint before cutting so I’ll just have to do a paint scheme that goes with plywood once the rain stops.

Welcome fellow scratch builder!​

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[Hobie1dog]

To the forum, be sure to put a picture up when it's finished.

 

[cwbullet]

Welcome to the hobby. I live in GA and fly in SC. We welcome you to fly with us.

 

[billpr]

Like the fins. Looks awesome. Keep us posted.

 

[Swifted]

So I did fillets with jb weld steel stick epoxy, which worked reasonably well. They are mostly for appearance since this isn’t going to be moving fast. Primer and another coat of the bondo spot filler which I like because it dries super fast and sands really easily. Going to go with a gray base coat and continue the pattern on the fins down the body tube in blue. Waiting on some bt-50 which I very unwisely ordered from Amazon.
I am considering using medium chipboard which is slightly thicker than the cardboard on the back of a notebook for centering rings if anybody has done anything similar for up to an E motor.

Since I’m doing the scratch built thing and I had some 1oz eipstop laying around I’m going to make an octagonal chute. However I really hate sewing coated nylon and I was wondering if anybody has used contact cement to roll seams on nylon and then small aluminum grommets to attach the shrouds.

Pictures aren’t amazing but I feel like I should put them up anyway

 

[Glasspack]

Very nice.........

What is the blue piece in the cut out designs of the fins ? Almost looks like a thin sheet
of something laminated between plys

 

[Swifted]

Very nice.........

What is the blue piece in the cut out designs of the fins ? Almost looks like a thin sheet
of something laminated between plys

It’s epoxy with a powder pigment mixed in

 

[Glasspack]

So...... a nice looking Epoxy fill in the cut outs
Got it....

 

[Swifted]

So...... a nice looking Epoxy fill in the cut outs
Got it....

It wasn’t all that difficult to do, just put the fins on a piece of acrylic and poured the epoxy in then laid another piece of acrylic on top and clamped it down

 

[Swifted]

Calling this done, going to do first flight on a d12 at the end of the month. I’ve come to terms with my mediocre painting skills, but highly recommend the Amazon special 4 oz hvlp paint sprayer I got. It puts out cheap acrylic craft paint thinned with water at least as well as I can do it with a rattle can. Going to call it stained glass, just waiting on a vinyl sticker from my wife’s cricut.

 

[lr64]

Looks pretty good to me. Will look better at 700 feet, assuming you can still see it.

 

[neil_w]

Very cool fins.

So I did fillets with jb weld steel stick epoxy, which worked reasonably well. They are mostly for appearance since this isn’t going to be moving fast.

That’s heavy stuff for cosmetics. Consider using something lighter in the future.

Waiting on some bt-50 which I very unwisely ordered from Amazon.

*Highly* recommend Balsa Machining for that sort of thing.

 

[Swifted]

Very cool fins.

That’s heavy stuff for cosmetics. Consider using something lighter in the future.

*Highly* recommend Balsa Machining for that sort of thing.

To be fair the whole rocket is an exercise in cosmetics. I am learning to trust wood glue, even though I know how strong it is with years of building furniture. I am absolutely terrible with epoxy and fiberglass work which is why I went with something easy and heavy. I’ll start looking for a mentor for some of the more technical parts of building.

I’ll look into balsa machining, I got irritated with estes and a couple of other places wanting $10 shipping for $6 of tubes. I paid the price in time wasted waiting for them to come in.

 

[Swifted]

Got to launch today on a D12. It launched great, and had a perfect flight. Then literally everything went wrong. Ejection charge somehow blew out the centering rings, and the swivel on the chute worked loose from the eye bolt. Recovered in 3 pieces… parachute wrapped up in a ball, followed by the nose cone tied to the motor mount, and the body tube buried about 4 inches in the dirt.

Other than the absent centering rings, there is no damage to anything. I’ll get some plywood cut for centering rings and clean out the dirt this weekend. I’ll definitely be ready for a second attempt at next month’s launch.

I thought it was weird that it launched so well and couldn’t hold up to the ejection charge though. I did fillets with wood glue on the back side of the rear centering ring, though looking at it doesn’t really seem like it soaked in very much. Definitely no damage to the paper. I’ve used epoxy for most everything else I’ve built and even the 5 minute stuff seems more forgiving.